NEW YORK (

TheStreet

) -- Drug and medical device maker

Abbott Laboratories

(ABT) - Get Report

saw earnings drop 14% during the first quarter as it posted an 11.5% decline in total operating income due to an after-tax charge related to the acquisition of Solvay Pharmaceuticals.

For the quarter ended March 31, the company reported earnings of $864 million, or 55 cents a share, down from earnings of $1.27 billion, or 64 cents a share, in the same period a year ago.

Non-GAAP net earnings, which exclude specific items, came in at 91 cents a share, slightly ahead of analysts' expectations of 90 cents.

Net sales increased 17.4% to $9.04 billion, driven by double-digit growth in each of Abbott's three major business categories.

"Stronger-than-expected sales helped us deliver 12% ongoing earnings-per-share growth in the first quarter," Chairman and CEO Miles White said in press statement. "Growth was balanced across our three key strategic business categories -- durable growth, proprietary pharmaceuticals and innovation-driven devices -- reflecting healthy performance across our global operations, including continued rapid growth in emerging markets."

Sales at its durable growth business increased 24.3%, primarily due to strong established pharmaceuticals sales growth, including the contribution from the Solvay Pharmaceuticals and Piramal Healthcare Solutions acquisitions, and the 15.8% growth in sales at international nutritionals.

Operating income dropped 11.5% to $1.3 billion from $1.47 billion as the company recorded after-tax charges of $81 million, or 5 cents a share, in the quarter, associated with the acquisition of Solvay.

Abbott confirmed its 2011 full-year earnings guidance of $4.54 to $4.64 a share. The midpoint of this guidance range reflects growth of 10% over 2010.

Management forecasts specified items for 2011 of about 84 cents a share, primarily associated with acquisition initiatives and in-process R&D. Including these specified items, projected GAAP earnings would be $3.70 to $3.80 per share for the year.

Shares of Abbott closed down 0.4% at $51.09 on Tuesday, and were dropping slightly in Wednesday's premarket trading to $51.

--Written by Theresa McCabe in Boston.

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